TALK ABSTRACT:
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Using high spatial resolution and sensitivity of the Hubble Space
Telescope and 8-10 m ground-based telescopes, we may study nearby
circumstellar disks in detail. The observations elucidate disk geometries
and dust composition and in an ensemble fashion teach us about the
evolution of disks and the timescales for planet formation within them. 
In this talk, I will show imaging and spectroscopy of disks around stars
which are all about 10 Myr old, yet which vary dramatically in physical
size, morphology and composition.  Even at this young age, planets may be
modifying their environments.  At older ages, the signature of terrestrial
planet formation have been elusive, but I will discuss one remarkable 
300 Myr old star.